Disposable diaper with portion on skin-side sheet to prevent passage of urine or other bodily waste

ABSTRACT

In a disposable diaper in which an absorbent body is provided between a water-repellent outer sheet and a hydrophilic skin-side sheet made of a nonwoven fabric, raisable strips made of a nonwoven fabric are provided at the opposite sides of the skin-side sheet, elastic threads for raisable gathers are provided in inner edge portions of the raisable strips and the outer edge portions of the raisable strips are adhered to the skin-side sheet, an ooze preventing portion for preventing an ooze of urine and other bodily waste is formed at opposite end portions of the skin-side sheet. Therefore, even if urine and other bodily waste permeate into the skin-side sheet, they do not ooze out from the end portion of the skin-side sheet.

TECHNICAL FIELD

The present invention relates to a disposable diaper capable ofeffectively and inexpensively preventing urine and other bodily wastefrom oozing out from an end portion of a skin-side sheet.

BACKGROUND ART

A known disposable diaper is such that an absorbent body is providedbetween an water-repellent outer sheet and a hydrophilic skin-side sheetmade of a nonwoven fabric, water-repellent raisable strips are providedat the opposite sides of the skin-side sheet, elastic threads forraisable gathers are provided at inner edge portions of the raisablestrips and outer edge portions of the raisable strips are adhered to theskin-side sheet.

In the above disposable diaper, a lateral leak of urine and other bodilywaste is prevented by the raised gathers formed by the elastic threadsprovided in the raisable strips.

However, since the skin-side sheet is hydrophilic, if urine and the likepermeate into this skin-side sheet, there is a problem that they mayooze out from an end portion of the skin-side sheet to stain clothes.

In view of this, a disposable diaper has been proposed in which an endof the outer sheet is rolled up to wrap an end of the skin-side sheetand is adhered to the upper surface of the skin-side sheet, so that evenif urine or other bodily waste oozes out from the end portion of theskin-side sheet, clothes are not stained by the presence of the rolledup outer sheet. However, this disposable diaper requires an operationstep of rolling up the end portion of the outer sheet, leading to anincreased production cost.

In view of the problem residing in the prior art, an object of thepresent invention is to provide a disposable diaper capable ofeffectively and inexpensively preventing urine and other bodily wastefrom oozing out from an end portion of a skin-side sheet.

DISCLOSURE OF THE INVENTION

The invention is directed to a disposable diaper in which an absorbentbody is provided between a water-repellent outer sheet and a hydrophilicskin-side sheet made of a nonwoven fabric, raisable strips made of anonwoven fabric are provided at the opposite sides of the skin-sidesheet, elastic threads for raisable gathers are provided in inner edgeportions thereof and the outer edge portions of the raisable strips areadhered to the skin-side sheet, wherein an ooze preventing portion forpreventing an ooze of urine and other bodily waste is formed at an endportion of the skin-side sheet.

According to the invention, since the ooze preventing portion is formedat the end portion of the skin-side sheet, even if urine and otherbodily waste permeate into the skin-side sheet, they do not ooze outfrom the end portion of the skin-side sheet.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a front view of an inventive disposable diaper in itsdeveloped state,

FIG. 2 is an exploded perspective view of the disposable diaper,

FIGS. 3A, 3B and 3C are schematic sections along A—A of FIG. 1,respectively, and

FIG. 4 is a front view of the disposable diaper in its used state.

BEST MODE FOR CARRYING OUT THE INVENTION

Hereinafter, one embodiment of the present invention is described indetail with reference to the accompanying drawings. FIG. 1 is a frontview of an inventive disposable diaper in its developed state, FIG. 2 isan exploded perspective view of the disposable diaper, FIGS. 3A, 3B and3C are schematic sections along A—A of FIG. 1, respectively, and FIG. 4is a front view of the disposable diaper in its used state.

As shown in FIG. 2, the disposable diaper is basically comprised of anouter sheet 1, an absorbent body 2, a skin-side sheet 3, and a pair ofleft and right raisable strips 4.

The outer sheet 1 is formed of a nonwoven fabric made of synthetic resinfibers having water repellency or a synthetic resin film, and legopenings S are formed at the opposite sides of a crotch portion Rbetween a front part P and a rear part Q.

A plurality of elastic threads 5 for waist gathers are provided on theupper surfaces of the front and rear parts P, Q of the outer sheet 1while being stretched in widthwise direction, and a plurality of elasticthreads 6 for leg gathers are provided on the upper surfaces of theopposite leg openings S while being stretched in lengthwise direction.

Further, a frontal tape 7 is attached to the lower surface of the frontpart P of the outer sheet 1, and fastening tapes 8 are respectivelyattached to the opposite sides of the rear part Q between the outersheet 1 and the skin-side sheet 3 or between the outer sheet 1 and theraisable strips 4 so as to assemble the disposable diaper in a 3D mannerby being adhered to the frontal tape 7 as shown in FIG. 4 when thedisposable diaper is used.

The absorbent body 2 is formed of a mixture of natural pulp fibers,synthetic resin fibers and a high water-absorbent polymer material or bylaminating these materials, and is a flat member which is about one sizesmaller than the outer sheet 1, substantially in the form of a rectangleand wrapped in a tissue paper. This absorbent body 2 is adhered to theupper surface of the outer sheet 1.

The skin-side sheet 3 is formed of a hydrophilic nonwoven fabric made ofsynthetic resin fibers and has the same outer configuration as the outersheet 1. The lower surface of the skin-side sheet 3 and the uppersurface of the outer sheet 1 are substantially entirely adhered to eachother with the absorbent body 2 and the elastic threads 5, 6 providedtherebetween. The skin-side sheet 3 may have a rectangular shape havinga width equal to a spacing between the leg openings S.

The left and right raisable strips 4 are formed of a nonwoven fabricmade of synthetic resin fibers having water repellency, havesubstantially the same length as the outer sheet 1 and the skin-sidesheet 3, and are formed at portions corresponding to the leg openings Swith leg openings having the same shape.

The respective raisable strips 4 have their inner edge portions 4 afolded downwardly and inwardly. The inner edge portions 4 a cover theopposite sides of the upper surface of the absorbent body 2 and thelower surfaces of outer edge portions 4 b are adhered to the uppersurface of the skin-side sheet 3.

Elastic threads 9 for raisable gathers are provided in the inner edgeportions 4 a of the respective raisable strips 4 while being stretchedsubstantially over the entire length of the raisable strips 4.

The respective elastic threads 5, 6, 9 are made of strip-shaped orthread-shaped natural rubber or synthetic rubber, and the waist gathers,raisable gathers and leg gathers are naturally formed by the shrinkingforces of the elastic threads 5, 6, 9.

The most significant feature of the present invention is that an oozepreventing portion for preventing an ooze of urine and the like isprovided at opposite end portions of the hydrophilic skin-side sheet 3.One example of the ooze preventing portion is a water repelled portion10 formed by applying an adhesive such as a hot melt adhesive to the endportion of the skin-side sheet 3 and causing the adhesive to permeateinto clearances between fibers of the nonwoven fabric as shown in FIG.3A. In the case of such a construction, the skin-side sheet may not be anonwoven fabric made of thermoplastic resin fibers.

Alternatively, as shown in FIG. 3B, a treatment may be given to preventan ooze of urine and the like by heat-sealing the end portion of theskin-side sheet 3 to fill up clearances between the fibers of thenonwoven fabric, thereby forming a first film portion 11 a. In the caseof such a construction, a nonwoven fabric made of thermoplastic resinfibers is used for the skin-side sheet 3 since the fibers of theskin-side sheet 3 need to be melted and made into a film by the heat ofheat-sealing. However, it is sufficient for the nonwoven fabric of theskin-side sheet 3 to possess such thermoplasticity as to be made into afilm by heat-sealing, and not all the fibers forming the nonwoven fabricneed to be thermoplastic resin fibers, i.e. fibers having nothermoplasticity may be mixed. It should be noted that an ultrasonicfusing means may be adopted instead of heat-sealing.

Further as shown in FIG. 3C, the respective end portions of theskin-side sheet 3 and the outer sheet 1 are joined by heat-sealing, anda first film portion 11 c may be formed by at least filling upclearances between the fibers of the nonwoven fabric of the skin-sidesheet 3. Since the outer sheet 1 is made of a water-repellent material,the ooze preventing portions can be formed by making the skin-side sheet3 into a film to lose water permeability. Regardless of whether theouter sheet 1 is a nonwoven fabric or a film, it is preferably made of athermoplastic material as described above like the skin-side sheet 3.The heat-sealed portion can be made into a film merely by joining thesheets 1 and 3 by means of heat-sealing.

As shown in FIG. 3B, second film portions 11 b may be formed by makingthe raisable strips 4 and the skin-side sheet 3 inwardly of the firstfilm portions 11 a into films while joining them by means ofheat-sealing. Clearances between the fibers of the nonwoven fabrics ofthe raisable strips 4 and the skin-side sheet 3 are filled up and theraisable strips 4 and the skin-side sheet 3 are joined to form the filmportions 11 b. This construction is further effective in preventing theooze of urine and the like since ooze prevention is performed at twostages.

Further, as shown in FIG. 3C, second film portions 11 d may be formed byjoining the raisable strips 4 and the skin-side sheet 3 inwardly of thefirst film portion 11 c by means of heat-sealing. It should be notedthat the first film portion may be formed by the skin-side sheet 3 andthe raisable strips 4 and the second film portions may be formed by theskin-side sheet 3 and the outer sheet 1.

The water repelled portions 10 by the hot melt adhesive at the endportion of the skin-side sheet 3 and the film portions 11 a, 11 c formedby heat-sealing preferably extend over the entire outer periphery of theskin-side sheet 3 as shown in chain double-dashed line in FIGS. 1 and 2in view of ooze prevention of urine and other bodily waste.

In the disposable diaper constructed as above, the water repelledportions 10 and the film portions 11 a, 11 c for the ooze preventingtreatment of urine and the like are formed at the end portion of thehydrophilic skin-side sheet 3. Accordingly, even if urine or the likepermeates into the skin-side sheet 3, there is no danger of staining theclothes since the permeated urine and the like do not ooze out from theend portion of the skin-side sheet 3.

Further, since it is not necessary, unlike the prior art, to roll up theend portion of the outer sheet 1 to wrap the end portion of theskin-side sheet 3, an operation step of rolling up the end of the outersheet 1 no longer necessary, contributing to a decrease in productioncost.

Furthermore, since the outer edges of the outer sheet 1, the skin-sidesheet 3 and the raisable strips 4 can be aligned, displacements thereofwhen they are placed one over another during manufacturing can beprevented.

If the second film portions 11 b or 11 d is formed by joining theraisable strips 4 and the skin-side sheet 3 by means of heat-sealing,urine and other bodily waste permeated into the skin-side sheet 3 do notooze out beyond the film portions 11 b, 11 d. Therefore, an ooze ofurine and the like can be more effectively prevented.

Although the invention is applied to the disposable diaper in theforegoing embodiment, it is, of course, also applicable to suchdisposable underpants that the first absorbent body is mounted on theskin-side sheet placed on the outer sheet.

INDUSTRIAL APPLICABILITY

As described above, the inventive disposable diaper is useful asdisposable diapers or disposable underpants which can effectively andinexpensively prevent an ooze of urine and bodily waste from the endportion of the skin-side sheet.

1. A disposable diaper, comprising: a water-repellent sheet; a skin-sidesheet joined with said water-repellant sheet; an absorbent body disposedbetween the water-repellent sheet and the skin-side sheet; and saidskin-side sheet being comprised of fibers arranged as a nonwoven fabrichaving clearances between the fibers, said skin side sheet including ahydrophilic region and an ooze preventing portion extending at leastpartially along opposite sides of said skin-side sheet, said oozepreventing portion separating said hydrophilic region from a peripheraledge of said skin-side sheet over an extent of said ooze preventingportion, said ooze preventing portion of said skin-side sheet beingrendered impermeable to a passage of water from said hydrophilic regionto said peripheral edge by permeation of an adhesive into the clearancesbetween the fibers whereby migration of bodily waste from saidhydrophilic region to said peripheral edge across said ooze preventingportion is prevented.
 2. A disposable diaper according to claim 1,further comprising raisable strips made of a nonwoven fabric andincluding edge portions adhered to the skin-side sheet at said oppositesides of the skin-side sheet.
 3. A disposable diaper according to claim2, wherein: said water-repellent sheet and said skin-side sheet haveapproximately a same outer configuration; and said peripheral edge ofsaid skin-side sheet and respective peripheral edges of saidwater-repellent sheet and said raisable strips are in mutual alignment.4. A disposable diaper according to claim 1, wherein said oozepreventing portion extends continuously over substantially an entireouter periphery of the skin-side sheet.
 5. A disposable diaper accordingto claim 1, wherein adhesive is a hot melt adhesive.
 6. A disposablediaper according to claim 1, wherein said skin-side sheet includes asecond ooze preventing portion located adjacent to said ooze preventingportion, said second ooze preventing portion of said skin-side sheetbeing water-impermeable thereby preventing migration of bodily wastethereacross.
 7. A disposable diaper, comprising: a water-repellentsheet; an absorbent body; and a skin-side sheet formed of a nonwovenfabric comprised of fibers having clearances therebetween, saidskin-side sheet being joined to said water-repellant sheet with saidabsorbent body interposed therebetween, said skin-side sheet including ahydrophilic region and an ooze preventing portion extending at leastpartially along opposite sides of said skin-side sheet, said oozepreventing portion separating said hydrophilic region from a peripheraledge of said skin-side sheet over an extent of said ooze preventingportion, said ooze preventing portion being formed as a film by afilling up of the clearances between the fibers of said nonwoven fabric,thereby rendering the hydrophilic skin-side sheet water-impermeablewithin said ooze preventing portion to prevent migration of bodily wastethereacross from said hydrophilic region to said peripheral edge.
 8. Adisposable diaper according to claim 7, further comprising raisablestrips made of a nonwoven fabric and including edge portions adhered tothe skin-side sheet at said opposite sides of the skin-side sheet.
 9. Adisposable diaper according to claim 7, wherein said ooze preventingportion extends continuously over substantially an entire outerperiphery of the skin-side sheet.
 10. A disposable diaper, comprising: awater-repellent sheet; an absorbent body; and a hydrophilic skin-sidesheet formed of a nonwoven fabric comprised of fibers having clearancestherebetween, said hydrophilic skin-side sheet being joined to saidwater-repellant sheet with said absorbent body interposed therebetween,said hydrophilic skin-side sheet including an ooze preventing portionformed inward of a peripheral edge and extending at least partiallyalong opposite sides of said hydrophilic skin-side sheet by heat-sealinga region inwardly adjacent to the peripheral edge of the skin-side sheetto fill up the clearances between fibers of the nonwoven fabric, therebyrendering the hydrophilic skin-side sheet water-impermeable within saidooze preventing portion to prevent migration of bodily waste thereacrossfrom a region of said hydrophilic skin-side sheet inward of said oozepreventing portion to said peripheral edge.
 11. A disposable diaperaccording to claim 10, further comprising raisable strips made of anonwoven fabric and including edge portions adhered to the skin-sidesheet at said opposite sides of the skin-side sheet.
 12. A disposablediaper according to claim 11, wherein said ooze preventing portionextends continuously over substantially an entire outer periphery of theskin-side sheet.
 13. A disposable diaper according to claim 11, wherein:said raisable strips include a thermoplastic material; and saidhydrophilic skin-side sheet includes a second ooze preventing portionlocated adjacent to said ooze preventing portion, said second oozepreventing portion being formed by heat sealing the edge portions ofsaid raisable strips to the hydrophilic skin-side sheet adjacent to saidooze preventing portion to concomitantly join the raisable strips withthe hydrophilic skin-side sheet and form said skin-side sheet into afilm in which the clearances between the fibers are filled up over ajoined region corresponding to said second ooze preventing portion. 14.A disposable diaper, comprising: a water-repellent sheet formed of oneof a film and a nonwoven fabric, each which comprises a thermoplasticmaterial; an absorbent body; and a hydrophilic skin-side sheet formed ofa nonwoven fabric comprised of fibers having clearances therebetween, atleast a portion of said fibers including thermoplastic resin fibers,said hydrophilic skin-side sheet being joined to said water-repellantsheet with said absorbent body interposed therebetween, said hydrophilicskin-side sheet including an ooze preventing portion which is a filmportion formed by joining said hydrophilic skin-side sheet to saidwater-repellent sheet by heat-sealing which concomitantly forms saidhydrophilic skin-side sheet into a film in which the clearances betweenthe fibers are filled up over a joined region corresponding to said oozepreventing portion which extends at least partially along opposite sidesof said hydrophilic skin-side sheet.
 15. A disposable diaper accordingto claim 14, further comprising raisable strips made of a nonwovenfabric and including edge portions adhered to the skin-side sheet atsaid opposite sides of the skin-side sheet.
 16. A disposable diaperaccording to claim 14, wherein said ooze preventing portion extendscontinuously over substantially an entire outer periphery of theskin-side sheet.
 17. A disposable diaper according to claim 15, wherein:said raisable strips include a thermoplastic material; and saidhydrophilic skin-side sheet includes a second ooze preventing portionlocated adjacent to said ooze preventing portion, said second oozepreventing portion of said skin-side sheet having a material propertywhich lacks water permeability thereby preventing migration of bodilywaste thereacross, said second ooze preventing portion being formed byheat sealing the edge portions of said raisable strips to thehydrophilic skin-side sheet adjacent to said ooze preventing portion toconcomitantly join the raisable strips with the hydrophilic skin-sidesheet and form said skin-side sheet into a film in which the clearancesbetween the fibers are filled up over a joined region corresponding tosaid second ooze preventing portion.
 18. A method of making a disposablediaper, comprising: interposing an absorbent body between awater-repellent sheet and a hydrophilic skin-side sheet, saidhydrophilic skin-side sheet being formed of a nonwoven fabric comprisedof fibers having clearances therebetween, at least a portion of saidfibers including thermoplastic resin fibers; joining saidwater-repellent sheet to said hydrophilic skin-side sheet; and formingan ooze preventing portion extending at least partially along oppositesides inward of a peripheral edge of said hydrophilic skin-side sheet bytreating said hydrophilic skin-side sheet to fill up the clearancesbetween the fibers thereof, thereby forming a film portion which iswater-impermeable to passage of water across said ooze preventingportion from a region of said hydrophilic skin-side sheet inward of saidooze preventing portion to said peripheral edge.
 19. A method accordingto claim 18, further comprising adhering raisable strips made of anonwoven fabric having outer edge portions to the hydrophilic skin-sidesheet.
 20. A method according to claim 19, wherein: said raisable stripsare made of a nonwoven fabric including a thermoplastic material; andsaid step of adhering includes heat sealing outer edge portions of saidraisable strips to the hydrophilic skin-side sheet adjacent to said oozepreventing portion to concomitantly join the raisable strips with thehydrophilic skin-side sheet and form said skin-side sheet into a filmover a joined region corresponding to a second ooze preventing portionlocated adjacent to said ooze preventing portion.
 21. A method accordingto claim 18, wherein said step of treating in said step of formingincludes heat-sealing said skin-side sheet into the film portion.
 22. Amethod according to claim 18, wherein said step of treating in said stepof forming includes ultrasonically fusing said skin-side sheet into thefilm portion.
 23. A method according to claim 18, wherein: saidwater-repellent sheet is one of a film and a nonwoven fabric each whichcomprises a thermoplastic material; and said step of treating in saidstep of forming, and said step of joining said hydrophilic skin-sidesheet to said water-repellent sheet, are accomplished in a shared stepincluding heat-sealing which, in addition to joining the hydrophilicskin-side sheet to said water-repellent sheet, concomitantly forms saidskin-side sheet into the film portion over a joined region of saidhydrophilic skin-side sheet to said water-repellent sheet correspondingto said ooze preventing portion.
 24. A method according to claim 23,further comprising adhering raisable strips made of a nonwoven fabricincluding a thermoplastic material by heat sealing outer edge portionsthereof to the hydrophilic skin-side sheet adjacent to said joinedregion to concomitantly join the raisable strips with the hydrophilicskin-side sheet and form said skin-side sheet into a film over a secondjoined region corresponding to a second ooze preventing portion locatedadjacent to said ooze preventing portion.
 25. A method of making adisposable diaper, comprising: interposing an absorbent body between awater-repellent sheet and a hydrophilic skin-side sheet, saidhydrophilic skin-side sheet being formed of a nonwoven fabric comprisedof fibers having clearances therebetween; joining said water-repellentsheet to said hydrophilic skin-side sheet; and forming an oozepreventing portion extending at least partially along opposite sidesinward of a peripheral edge of said hydrophilic skin-side sheet byapplying an adhesive to the skin-side sheet and causing the adhesive topermeate into the clearances between the fibers thereby rendering thenonwoven fabric water-impermeable within said ooze preventing portion toprevent migration of bodily waste across said ooze preventing portionfrom a portion of said skin-side sheet inward of said ooze preventingportion to said peripheral edge.
 26. A disposable diaper according toclaim 25, wherein: said adhesive is a hot melt adhesive.